Field of the Invention
The present invention relates to a hollow silicon-based particle, a preparation method thereof and an anode active material for a lithium secondary battery including the same.
Description of the Related Art
Lithium secondary batteries recently receiving attention as power sources of portable and small electronic devices is a battery using an organic electrolyte and having high energy density exhibiting higher discharge voltage by twice or more than that of a common battery using an alkaline aqueous solution.
As an anode material of a lithium secondary battery, graphite is widely used, however graphite has small capacity per unit weight of 372 mAh/g, and thus, the manufacture of a lithium secondary battery having high capacitance is difficult.
An anode active material exhibiting higher capacitance than graphite, that is, a material (a lithium alloying material) forming an alloy with lithium electrochemically, such as silicon, tin, an oxide thereof, etc. exhibits high capacity of greater than or equal to about 1,000 mAh/g and low charge and discharge voltage of 0.3 to 0.5 V. Thus, the material receives attention as an anode active material for a lithium secondary battery.
However, the above-described material has the defect of inducing the change of a crystalline structure and increasing volume during forming an alloy with lithium electrochemically. In this case, physical contact loss may occur between electrode active materials formed by coating a powder or between an electrode active material and a current collector during charge and discharge, and the capacity decrease of a lithium secondary battery according to the progress of charge and discharge cycle may be great.
Therefore, for the manufacture of a lithium secondary battery having high capacity, the development of a novel silicon material that may effectively control the volume change is required, and an anode having good capacity, efficiency, and cycle life characteristics and replaceable with a common anode is necessary.